Do they have to be tinned, Laurie? You can get nice fresh lamb's kidneys from the butchers counter in Tesco's. I usually buy a couple to go with a casserole on a Friday.
If at first you don't succeed, sky diving isn't for you!
If you think I'm going to stagger down to the butcher at 7.00am , buy kidneys,bring them home, skin them, core them prepare a nice savoury sauce and cook them just because I fancy kidneys for breakfast you're wrong, any more than I would buy some beans and cook them up in tomato sauce bemuse I fancied beans on toast!
When my mother cooked stewing steak no matter how lean or how she struggled to take the fat off I couldn't eat it. She used to buy extra kidney for me. You forget those little things over time.